ST. PAUL, Minn. (AP) — Researchers studying water samples from the Mississippi and St. Croix rivers for fragments of Asian carp DNA say they found little evidence of bighead and silver carp in Minnesota.

The study released Thursday concludes that while the invasive fish are present in Minnesota, their numbers are likely relatively low.

Researchers analyzed water samples for DNA fragments released to the environment, called eDNA. They found silver carp eDNA in Iowa, where the fish are abundant, but none near St. Croix Falls in the St. Croix, or near the Coon Rapids Dam or below Lock and Dam No. 1 in the Mississippi.

Research team leader Peter Sorensen says despite the lack of eDNA evidence, there is reason to believe Asian carp are entering Minnesota waters from the south and could breed here.